<template>
  <div>
    <el-tree
      show-checkbox
      :data="menus"
      :props="defaultProps"
      :expand-on-click-node="false"
      node-key="catId"
      :default-expanded-keys="expandedKey"
      draggable
      :allow-drop="allowDrop"
      @node-drop="handleDrop"
    >
      <span class="custom-tree-node" slot-scope="{ node, data }">
        <span>{{ node.label }}</span>
        <span>
          <el-button
            v-if="node.level <= 2"
            type="text"
            size="mini"
            @click="() => append(data)"
          >
            Append
          </el-button>
          <el-button type="text" size="mini" @click="edit(data)">
            Edit
          </el-button>
          <el-button
            v-if="node.childNodes.length == 0"
            type="text"
            size="mini"
            @click="() => remove(node, data)"
          >
            Delete
          </el-button>
        </span>
      </span>
    </el-tree>

    <!-- 新增/修改 菜单对话框 -->
    <el-dialog
      :close-on-click-modal="false"
      :title="title"
      :visible.sync="dialogVisible"
      width="30%"
    >
      <el-form :model="category">
        <el-form-item label="分类名称">
          <el-input v-model="category.name" autocomplete="off"></el-input>
        </el-form-item>
        <el-form-item label="图标">
          <el-input v-model="category.icon" autocomplete="off"></el-input>
        </el-form-item>
        <el-form-item label="计量单位">
          <el-input
            v-model="category.productUnit"
            autocomplete="off"
          ></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="dialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="submitData">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
//这里可以导入其他文件（比如：组件，工具js，第三方插件js，json文件，图片文件等等）
//例如：import 《组件名称》 from '《组件路径》'

export default {
  //import引入的组件需要注入到对象中才能使用
  components: {},
  props: {},
  data() {
    return {
      updateNodes: [], //被拖拽时，要修改信息的节点
      maxLevel: 0, //最深层节点的层级
      title: "", //对话框的标题
      dialogType: "", //因为要复用对话框，所以设置对话框类型,新增时设为add，修改时设为edit
      category: {
        name: "",
        parentCid: 0,
        catLevel: 0,
        showStatus: 1,
        sort: 0,
        productUnit: "",
        icon: "",
        catId: null,
      },
      dialogVisible: false, //对话框的值 默认关闭
      menus: [],
      expandedKey: [], //设置删除后父菜单不闭合
      defaultProps: {
        children: "children",
        label: "name",
      },
    };
  },
  methods: {
    getMenus() {
      this.$http({
        url: this.$http.adornUrl("/product/category/list/tree"),
        method: "get",
      }).then((data) => {
        //alert(data.data);
        console.log("成功获取到菜单数据。。。", data.data.page);
        this.menus = data.data.page;
      });
    },
    //拖拽成功后的事件
    handleDrop(draggingNode, dropNode, dropType, ev) {
      console.log("handleDrop:", draggingNode, dropNode, dropType);
      //1、当前节点最新的父节点id
      let pCid = 0;
      let siblings = null;
      if (dropType == "before" || dropType == "after") {
        pCid =
          dropNode.parent.data.catId == undefined
            ? 0
            : dropNode.parent.data.catId;
        siblings = dropNode.parent.childNodes;
      } else {
        pCid = dropNode.data.catId;
        siblings = dropNode.childNodes;
      }

      //2、当前节点的最新顺序
      for (let i = 0; i < siblings.length; i++) {
        if (siblings[i].data.catId == draggingNode.data.catId) {
          //如果遍历的是当前正在拖动的节点
          let catLevel = draggingNode.level;
          if (siblings[i].level != draggingNode.level) {
            //当前节点层级发生变化
            catLevel = siblings[i].level;
            //修改他子节点的层级
            this.updateChildNodeLevel(siblings[i]);
          }

          this.updateNodes.push({
            catId: siblings[i].data.catId,
            sort: i,
            parentCid: pCid,
            catLevel: catLevel,
          });
        } else {
          //遍历兄弟节点
          this.updateNodes.push({ catId: siblings[i].data.catId, sort: i });
        }
      }
      console.log("updateNodes:", this.updateNodes);
      //3、当前节点的最新层级
      this.$http({
        url: this.$http.adornUrl("/product/category/update/sort"),
        method: "post",
        data: this.$http.adornData(this.updateNodes, false),
      }).then(({ data }) => {
        this.$message({
          message: "菜单顺序等修改成功",
          type: "success",
        });
        //刷新菜单
        this.getMenus();
        //展开菜单
        this.expandedKey = [pCid];
        //拖拽成功后清空这两个
        this.updateNodes = [];
        this.maxLevel = 0;
      });
    },
    //改变当前节点子节点的层级
    updateChildNodeLevel(node) {
      if (node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          var cNode = node.childNodes[i].data;
          this.updateNodes.push({
            catId: cNode.catId,
            catLevel: node.childNodes[i].level,
          });
          this.updateChildNodeLevel(node.childNodes[i]);
        }
      }
    },
    //拖拽时判定目标节点能否被放置。
    allowDrop(draggingNode, dropNode, type) {
      //1、被拖动的当前节点以及所在的父节点总层数不能大于三

      //1）、被拖动的当前节点的总层数
      console.log("allowDrop:", draggingNode, dropNode, type);
      //计算当前节点的总层数
      var level = this.countNodeLevel(draggingNode.data);
      //当前正在拖动的节点+父节点所在的深度不大于3即可
      let deep = this.maxLevel - draggingNode.data.catLevel + 1;
      console.log("正在拖动节点的深度：", deep);
      if (type == "inner") {
        console.log(
          `this.maxLevel:${this.maxLevel};draggingNode.data.catLevel:${draggingNode.data.catLevel};dropNode.level:${dropNode.level}`
        );
        //往目标节点里边拖动时，判断当前拖动节点的深度+目标节点的深度小于等于3才可拖动
        return deep + dropNode.level <= 3;
      } else {
        //否则往目标节点的前边或者后边拖动时，当前节点的深度+目标节点的父节点的层级小于等于3即可
        return deep + dropNode.parent.level <= 3;
      }
    },
    //统计当前被拖动节点的总层数
    countNodeLevel(node) {
      //找到所有子节点，求出最深层节点的深度
      if (node.children != null && node.children.length > 0) {
        for (let i = 0; i < node.children.length; i++) {
          if (node.children[i].catLevel > this.maxLevel) {
            this.maxLevel = node.children[i].catLevel;
          }
          this.countNodeLevel(node.children[i]);
        }
      }
    },
    //修改菜单方法
    edit(data) {
      console.log("要修改的数据。。", data);
      //修改时将对话框类型设置为edit
      this.dialogType = "edit";
      //修改时对话框标题设置为新增数据
      this.title = "修改分类";
      //复用新增对话框
      this.dialogVisible = true;

      //回显数据 获取当前节点最新的数据
      this.$http({
        url: this.$http.adornUrl(`/product/category/info/${data.catId}`),
        method: "get",
      }).then(({ data }) => {
        //请求成功
        console.log("要回显得数据", data);
        this.category.name = data.data.name;
        this.category.catId = data.data.catId;
        this.category.icon = data.data.icon;
        this.category.productUnit = data.data.productUnit;
        this.category.parentCid = data.data.parentCid;
      });
    },
    append(data) {
      console.log("append", data);
      //新增时将对话框类型设置为add
      this.dialogType = "add";
      //新增时对话框标题设置为新增数据
      this.title = "添加分类";
      //点击append弹出对话框
      this.dialogVisible = true;
      //设置新增菜单时 默认值
      this.category.parentCid = data.catId;
      this.category.catLevel = data.catLevel * 1 + 1; //层级转化为字符串
      //新增时清空回显数据
      this.category.name = "";
      this.category.catId = null;
      this.category.icon = "";
      this.category.productUnit = "";
      this.category.sort = 0;
      this.category.showStatus = 1;
    },

    //提交对话框数据
    submitData() {
      //判断对话框类型
      if ((this.dialogType = "add")) {
        this.addCategory();
      }
      if ((this.dialogType = "edit")) {
        this.editCategory();
      }
    },

    //修改三级分类数据
    editCategory() {
      //不能将整个category直接发送，要有选择的
      var { catId, name, icon, productUnit } = this.category;
      this.$http({
        url: this.$http.adornUrl("/product/category/update"),
        method: "post",
        data: this.$http.adornData({ catId, name, icon, productUnit }, false),
      }).then(({ data }) => {
        //修改保存成功后提示
        this.$message({
          message: "菜单修改成功",
          type: "success",
        });
        //修改保存成功后关闭对话框
        this.dialogVisible = false;
        //修改后重新获取菜单
        this.getMenus();
        //设置修改后需要默认展开的菜单  当前节点的父节点的data的catId
        this.expandedKey = [this.category.parentCid];
      });
    },

    //添加三级分类的方法
    addCategory() {
      this.$http({
        url: this.$http.adornUrl("/product/category/save"),
        method: "post",
        data: this.$http.adornData(this.category, false),
      }).then(({ data }) => {
        //新增成功后消息提示
        this.$message({
          message: "菜单保存成功",
          type: "success",
        });
        //保存成功后关闭对话框
        this.dialogVisible = false;
        //新增后重新获取菜单
        this.getMenus();
        //设置新增后需要默认展开的菜单  被删除的节点的父节点的data的catId
        this.expandedKey = [this.category.parentCid];
      });
      console.log("提交的三级分类数据", this.category);
    },

    remove(node, data) {
      var ids = [data.catId];
      //删除前弹框提示
      this.$confirm(`是否删除【${data.name}】菜单?`, "提示", {
        confirmButtonText: "确定",
        cancelButtonText: "取消",
        type: "warning",
      })
        .then(() => {
          this.$http({
            url: this.$http.adornUrl("/product/category/delete"),
            method: "post",
            data: this.$http.adornData(ids, false),
          }).then((data) => {
            //删除成功后消息提示
            this.$message({
              message: "菜单删除成功",
              type: "success",
            });
            //删除后重新获取菜单
            this.getMenus();
            //设置需要默认展开的菜单  被删除的节点的父节点的data的catId
            this.expandedKey = [node.parent.data.catId];
          });
        })
        .catch(() => {});
      console.log("remove", node, data);
    },
  },
  //计算属性 类似于data概念
  computed: {},
  //监控data中的数据变化
  watch: {},

  //声明周期 - 创建完成（可以访问当前this实例）
  created() {
    this.getMenus();
  },
  //声明周期 - 挂载完成（可以访问DOM元素）
  mounted() {},
  beforeCreate() {}, //生命周期 - 创建之前
  beforeMount() {}, //生命周期 - 挂载之前
  beforeUpdate() {}, //生命周期 - 更新之前
  updated() {}, //生命周期 - 更新之后
  beforeDestroy() {}, //生命周期 - 销毁之前
  destroyed() {}, //生命周期 - 销毁完成
  activated() {}, //如果页面有keep-alive缓存功能，这个函数会触发
};
</script>
<style scoped>
</style>